From 4f411c42fbb76b8be116c889306ba4692ec14b84 Mon Sep 17 00:00:00 2001
From: Harrison <yunyangdeng@gmail.com>
Date: Sun, 26 Apr 2020 20:56:10 -0500
Subject: [PATCH] Added conversion from world coordinates to utilities.

Respective tests also added.
---
 .../islandsurvivalcraft/Utilities.java        | 44 +++++++++++++++++++
 .../islandsurvivalcraft/UtilitiesTest.java    | 32 ++++++++++++++
 2 files changed, 76 insertions(+)

diff --git a/src/main/java/ca/recrown/islandsurvivalcraft/Utilities.java b/src/main/java/ca/recrown/islandsurvivalcraft/Utilities.java
index ad26006..907ff2d 100644
--- a/src/main/java/ca/recrown/islandsurvivalcraft/Utilities.java
+++ b/src/main/java/ca/recrown/islandsurvivalcraft/Utilities.java
@@ -4,7 +4,11 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map.Entry;
 
+import ca.recrown.islandsurvivalcraft.Types.Point2;
+
 public class Utilities {
+    public final static int CHUNK_SIZE = 16;
+
     public static <K, V> HashMap<V, ArrayList<K>> invertHashMap(HashMap<K, V> hashMap) {
         HashMap<V, ArrayList<K>> res = new HashMap<>();
         for (Entry<K, V> entry : hashMap.entrySet()) {
@@ -25,4 +29,44 @@ public class Utilities {
         int res = Math.abs(value) + add;
         return negative ? - res : res;
     }
+
+    public static Point2 worldToChunkCoordinates(int x, int y) {
+        int xRes = 0;
+        if (x < 0) {
+            xRes = (int) Math.floor((float) x / CHUNK_SIZE);
+        } else {
+            xRes = x / CHUNK_SIZE;
+        }
+        int yRes = 0;
+        if (x < 0) {
+            yRes = (int) Math.floor((float) y / CHUNK_SIZE);
+        } else {
+            yRes = y / CHUNK_SIZE;
+        }
+        return new Point2(xRes, yRes);
+    }
+
+    public static Point2 worldToChunkCoordinates(Point2 worldCoordinates) {
+        return worldToChunkCoordinates(worldCoordinates.x, worldCoordinates.y);
+    }
+
+    public static Point2 worldToLocalChunkCoordinates(int x, int y) {
+        int xRes = 0;
+        if (x < 0) {
+            xRes = CHUNK_SIZE + (x % CHUNK_SIZE);
+        } else {
+            xRes = x % CHUNK_SIZE;
+        }
+        int yRes = 0;
+        if (y < 0) {
+            yRes = CHUNK_SIZE + (y % CHUNK_SIZE);
+        } else {
+            yRes = y % CHUNK_SIZE;
+        }
+        return new Point2(xRes, yRes);
+    }
+
+    public static Point2 worldToLocalChunkCoordinates(Point2 worldCoordinates) {
+        return worldToChunkCoordinates(worldCoordinates.x, worldCoordinates.y);
+    }
 }
\ No newline at end of file
diff --git a/src/test/java/ca/recrown/islandsurvivalcraft/UtilitiesTest.java b/src/test/java/ca/recrown/islandsurvivalcraft/UtilitiesTest.java
index 6af8655..5ec6be0 100644
--- a/src/test/java/ca/recrown/islandsurvivalcraft/UtilitiesTest.java
+++ b/src/test/java/ca/recrown/islandsurvivalcraft/UtilitiesTest.java
@@ -9,6 +9,8 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestInstance;
 import org.junit.jupiter.api.TestInstance.Lifecycle;
 
+import ca.recrown.islandsurvivalcraft.Types.Point2;
+
 /**
  * Unit test for simple App.
  */
@@ -48,4 +50,34 @@ public class UtilitiesTest {
     public void testMagnitudeAddNegative() {
         assertEquals(-2, Utilities.addMagnitude(-1, 1));
     }
+
+    @Test
+    public void testWorldToChunkCoordinatesNegativePerfect() {
+        assertEquals(new Point2(-4, -3), Utilities.worldToChunkCoordinates(-64, -48));
+    }
+
+    @Test
+    public void testWorldToChunkCoordinatesNegativeOff() {
+        assertEquals(new Point2(-4, -3), Utilities.worldToChunkCoordinates(-55, -33));
+    }
+
+    @Test
+    public void testWorldToChunkCoordinatesPositivePerfect() {
+        assertEquals(new Point2(4, 5), Utilities.worldToChunkCoordinates(64, 80));
+    }
+
+    @Test
+    public void testWorldToChunkCoordinatesPositiveOff() {
+        assertEquals(new Point2(4, 5), Utilities.worldToChunkCoordinates(67, 84));
+    }
+
+    @Test
+    public void testWorldToLocalCoordinatesNegative() {
+        assertEquals(new Point2(2, 5), Utilities.worldToLocalChunkCoordinates(-62, -27));
+    }
+
+    @Test
+    public void testWorldToLocalCoordinatesPositive() {
+        assertEquals(new Point2(7, 3), Utilities.worldToLocalChunkCoordinates(39, 83));
+    }
 }